Experiments performed on presses of a conventional type, such as the press disclosed in German patent Nos. DE-12 78 883, and DE-16 27 841 have shown that the output can only be increased by increasing the number of the flexible drainage lines, if the press chamber is increased by the same ratio. The optimal number of drainage lines is therefore dependent on the volume of the press, and if an optimum number of drainage lines is selected, an optimum dejuicing results from the start of the pressing operation till its end. This fact is an apparent contradiction in view of the fact, that the goods to be drained from juice, and dispersed between the drainage lines may be optimally dejuiced only in a relatively narrow region near the drainage lines, while the remainder of the goods to be drained just about retain their liquids during dejuicing. Addition of any additional drainage lines would not, however, lead to any useful result, according to past experience, and would only lead to further difficulties during loosening of goods drained of juice. By an increased number of drainage lines within the press chamber the mixing affect of pressed mash to partly pressed and fresh mash is reduced.
In such a case a better dejuicing is not possible, even if the pressure of the pressing operation is increased. Although additional juice can be obtained this way, the mash is simultaneously "overpressed", so that a pulp-like substance results, which leads to an undesired clouding of the juice.
Based on the fact, that the mash may be optimally and gently dejuiced only in a relatively thin layer around the drainage lines, a volumemetrically higher juice exploitation may also be obtained, if the number of press cycles is increased, and if the pressed goods are intensively loosened between the individual press operation. This method of operation is, however, uneconomical in view of the fact that the pressing operation is considerably prolonged.